SIGNIFICANCE OF PHYLOGENETIC STUDIES 47 



ever, brought again the sagittal division to the foreground. 

 He distinguished the palaeocerebellum, which is composed 

 of the vermis, the flocculus and the paraflocculus, from the 

 neocerebellum, consisting of the hemispheres. He did not 

 confine himself to the mammal group, but studied all classes 

 of vertebrates. In fxshes, amphibians, reptiles and in birds 

 the palaeocerebellum, the older part, is only found. In 

 the lowest group of mammals the neocerebellum appears. 

 There it is very small but grows bigger in higher mammals, 

 being largest in man. 



Primarms 



Flocculus 

 and 



Paraflocculus 



Fig. 10. Scheme of the Cerebellum 

 Black = palaeocerebellum. White = neocerebellum. (After Edinger) 



Such were the different views held, when I got the oppor- 

 tunity of forming a personal opinion regarding this problem. 

 I saw the brain of a man who during life had never shown 

 any cerebellar symptom, but whose cerebellum on the left 

 side was atrophied. The brainstem and the cerebellum 

 were examined in a complete series of sections, stained after 

 Weigert-Pal, van Gieson and with carmine. It was found 

 that the atrophy of the cortex cerebelli was limited to the 

 neocerebellum of Edinger, the vermis, flocculus and para- 

 flocculus remaining normal. Afterwards I saw other brains 



